Combustion of N-Decane plus air Mixtures To Investigate Laminar Burning Velocity Measurements At Elevated Temperatures

The combustion characteristics of n-decane+air mixtures are experimentally investigated through laminar burning velocity measurements at 1 atm pressure and higher initial temperatures using an externally heated diverging channel (EHDC) method. Up to 610 K mixture temperature over an equivalence ratio range of 0.7-1.4, laminar burning velocities are reported with an accuracy of +/- 5%. The current measurements exhibit a good match with existing experimental measurements, and agree closely with the predictions of Zhao, LLNL and PoliMi mechanisms at different mixture temperatures. The present measurements show an excellent match of temperature exponent (alpha) variation with equivalence ratio (phi) with the predictions of distinct kinetic models as well as experimental measurements. This study reveals that a substantial scatter exists among the predictions of different kinetic models. A variation of 20-30 cm/s in the burning velocity is observed at 610 K mixture temperature. Reaction R16 (H + HO2 = H-2 + O-2), which inherently reduces the burning velocity becomes insignificant at an elevated mixture temperature of 610 K, and the reaction R15 (H + HO2 = 2OH) plays a dominant role in accelerating the flame propagation. From reaction pathway diagrams, it is clear that a higher burning velocity at 610 K is associated with the increased reaction rate. The elemental-flux value associated with the formation of C2H3 from C2H4 at 610 K mixture temperature is approximately equal to 34% higher in comparison to the 470 K mixture temperature.